Performance Testing

netperf is a benchmark that
can be used to measure the performance of
many different types of networking including Unix Domain Sockets and
TCP and UDP via BSD Sockets. It provides tests for both unidirectional
throughput and end-to-end latency.
Netperf
page.

bing by Pierre Beyssac
determines bandwidth on
a point-to-point link by sending ICMP ECHO_REQUEST packets and
measuring their roundtrip times for different packet sizes on each end
of the link.